openapi: 3.0.3
info:
  title: Buildkite Agent API
  version: v3
  description: |
    Public subset of the Buildkite Agent API consumed by the open-source agent (Go) to register,
    accept, and finish jobs. Most endpoints are reserved for internal use; only the documented
    public endpoints are stable. Authenticated with an Agent Token (`Authorization: Token <agent-token>`).
  contact:
    name: Buildkite Agent
    url: https://github.com/buildkite/agent
servers:
- url: https://agent.buildkite.com/v3
  description: Standard Agent API
- url: https://agent-edge.buildkite.com/v3
  description: Edge Agent API (adds gRPC methods alongside JSON)
security:
- agentToken: []
tags:
- name: Metrics
- name: Stacks
paths:
  /metrics:
    get:
      tags: [Metrics]
      summary: Get Cluster Agent Metrics
      operationId: getMetrics
      description: Returns current agent and job counts for the cluster associated with the agent token.
        Used by autoscalers (Lambda scaler, agent-stack-k8s, custom controllers) to size agent pools.
      responses:
        '200':
          description: Cluster metrics payload
          content:
            application/json:
              schema:
                type: object
                properties:
                  agents:
                    type: object
                    properties:
                      idle:
                        type: integer
                      busy:
                        type: integer
                      total:
                        type: integer
                  jobs:
                    type: object
                    properties:
                      scheduled:
                        type: integer
                      running:
                        type: integer
                      total:
                        type: integer
                  organization:
                    type: object
                    properties:
                      slug:
                        type: string
  /stacks:
    get:
      tags: [Stacks]
      summary: Get Stack Configuration For Self-Hosted Queues
      operationId: getStacks
      description: Returns the desired stack configuration for a self-hosted queue's controller process.
        The controller watches the queue for jobs and runs agents on demand.
      responses:
        '200':
          description: Stack configuration payload
components:
  securitySchemes:
    agentToken:
      type: http
      scheme: bearer
      bearerFormat: Agent Token (sent as `Token <value>`)